Is it necessary to replace substrate in a planted tank?

[fishrancher]

My 29g FW planted has been set up for more than 3 years. I'm using a Penguin Bio-wheel 200B for filtration. PWC 50% every two (sometimes three) weeks. Previously, I had a Nova Extreme 2x24 watt and and a 20 watt bulb (and tin foil) in the plastic light included with the tank. I never had good results with moderate light plants, and their performance has diminished over time. I (finally) broke down and upgraded my lighting to Coralife (4 x 31 watt HO). I have started running 2 bulbs 12 hours and overlap the other 2 bulbs 4 hours (so 62 watts for 8 hours and 124 watts for 4 hours). I am dosing FlorinAxis (carbon source) and FlorminMulti (multinutrient with iron and iodine) per the label -- both are made by Brightwell Aquatics).

More light should mean more growth (and nutrient demand): so now I am concerned that my substrate might be spent. (Can't find the bag and can't remember the name -- bought it at the lfs, the substrate is red/clay colored and was recommended for a planted tank, with small, natural gravel over it -- if it's important I can run by the lfs tomorrow and see if I recognize the bag.)

At long last, here is the question: Is it necessary to replace the substrate in a planted tank after some period of time? Or can I keep adequate nutrients available long-term with fertilizers? The idea of disrupting a mature tank to replace substrate is a bit daunting, so I'm hoping this was just a crazy lfs idea to sell more dirt.

As long as I am asking, are the liquid ferts I'm using okay and/or should I be adding root tabs as well?

Thanks.

[jetajockey]

The short answer is yes, you'll be fine dosing liquid ferts. Root tabs won't hurt, though, and I do suggest putting them down under your heavy root feeders.

[Coursair]

+1 root tabs. Maybe shorten your photoperiod till you get them. That much light you may need CO2 paintball set up ?

[aqua_chem]

I think the substrate that you're describing is Flourite. Assuming that, then your substrate never really had very much nutrients in it to start with. Rather, most flora substrates are high CEC substrates that can take nutrients from the water column and store it in a form that root feeding plants can use. Most clay based substrates (Flourite) won't loose their CEC capacity any time soon. Those ferts should be ok, but I've heard from multiple places that Excel beats the pants off of florinAxis (better chemical substitute + Excel doubles as a algaecide). +2 on root tabs for any root feeders.



Your lack of CO2 is whats hurting you. Instead of getting an overpowered light fixture, you should have invested in a CO2 Regulator+tank. Right now you have an algae farm waiting to happen.

[fishrancher]

Thanks all. I know I'm a bit heavy on light but I got tired of not having enough. And I can always shorten the photoperiod. And I do think the substrate is flourite. Do any of you have any experience with the new Fluval Pressurized CO2 Kit 88 g with the disposable canisters?

Thanks again for the info re liquid ferts.

[fishrancher]

Yikes. So I checked out some customer reviews on the Fluval CO2 system and it looks like it's not a cost effective (or particularly convenient) way to go. Off to look for a CO2 set up.

[aqua_chem]

You had plenty of light before. I personally think that lowering the photoperiod to accommodate bright lights is crap because then I have less time to enjoy my tank. Better to have more appropriate lights and a longer photoperiod than Cadillac lighting and less quality time with the light.

Fluval co2 system is overpriced junk. Good call.

If you're open to suggestions, I would recommend the Milwaukee regulator. Budget friendly and many satisfied users. It has some very vocal opponents though, and with good reason, but if you're on a budget, it will do nicely. If you want to put more money in it (any man planted tank experts recommend that you put your extra money in your CO2 rather than lights), look at a nice dual stage regulator like a Victor.

[fishrancher]

I'm running 2 wpg for 8 hours and 4 wpg for 4 hours. I guess even 4 wpg doesn't seem out of the normal range from what I've read -- am I missing something? I increased the light because I basically never had much success on moderate or higher light requiring plants with my old set up (1.6 wpg of T5 and .7 wpg of T8). I do hear you on the CO2.

On that, I've definitely heard of the Milwaukee and will look into the Victor. Thanks.